Joshua, 29, will take on Miller at Madison Square Garden in the undefeated American's home city of New York.
Miller, with 23 wins and a draw, has never fought for a world title.
The 30-year-old will almost certainly be the heaviest opponent Joshua has faced as a professional having weighed 22st 7lbs in his last contest.
Miller - nicknamed 'Big Baby' - won 20 of his fights by knockout but Joshua represents a huge step-up in class.
Joshua said: "I am heading to the Big Apple and I plan to embrace the culture and leave with an appetite for more.
"It has been an honour and a blessing to fight at some of the best venues in the world and at home in the UK, not least Wembley Stadium, but the time has come to head across the Atlantic and defend my heavyweight titles in the USA.
"I am looking forward to taking on another challenge with a good boxer and a brilliant talker. It will be an exciting fight. I will leave nothing to chance and plan on dismantling Miller in style to make my mark." SHARE THIS STORY USING ANY OF THE BUTTON BELOW ⬇ PLACE YOUR TEXT ADVERT BELOW ⬇⬇⬇